Isolated Plasma Array Treatment Systems

ABSTRACT

Systems, methods, and apparatus are contemplated in which a tube cell that produces a dielectric barrier discharge (DBD) is individually configured to minimize the mixing of unwanted byproducts of the generated plasma with an exhaust air stream. The tube cell generates a DBD within a tube cell, such that oxidants or radicals are generated in an environment substantially separated from the exhaust stream. The generated oxidants are directed to intersect with the exhaust stream to minimize the generation of unwanted byproducts. The tube cells are further shaped and arranged in tube cell arrays to alter the flow dynamics of the exhaust stream and the oxidant or radical streams, including mixing of the streams.

This application claims the benefit of priority and is a continuation ofU.S. patent application Ser. No. 16/164,605 filed on Oct. 18, 2018,which claims the benefit of priority to U.S. provisional application No.62/573,950 filed on Oct. 18, 2017. This and all other extrinsicreferences referenced herein are incorporated by reference in theirentirety.

FIELD OF THE INVENTION

The field of the invention is exhaust treatment systems.

BACKGROUND

The background description includes information that may be useful inunderstanding the present invention. It is not an admission that any ofthe information provided herein is prior art or relevant to thepresently claimed invention, or that any publication specifically orimplicitly referenced is prior art.

Industry standards for engine emissions require engine pollutants to beminimized below a threshold level. While many catalysts can beintroduced to engine exhaust streams to render pollutants inert or tootherwise nullify the effects of engine pollutants, such catalystscannot operate at all engine temperatures. For example, see US PatentPublications 2011/0048251 and US2002/0153241, as well as U.S. Pat. Nos.5,518,698 and 8,794,574. Further, known methods suffer from generationof unwanted by products (e.g., HNO₂, HNO₃) by creating OH radical fromhydrogen rich gas streams, when then reacts with NO and NO₂ to form HNO₂and HNO₃, respectively.

All publications herein are incorporated by reference to the same extentas if each individual publication or patent application werespecifically and individually indicated to be incorporated by reference.Where a definition or use of a term in an incorporated reference isinconsistent or contrary to the definition of that term provided herein,the definition of that term provided herein applies and the definitionof that term in the reference does not apply.

Thus, there is a need for a system and method to efficiently introducecatalysts to exhaust streams at lower temperatures.

SUMMARY OF THE INVENTION

The inventive subject matter contemplates apparatus, systems, andmethods for treating an exhaust stream. A tube cell has an oxidizingflow path for an air stream (e.g., raw air, humid air, filtered air, airdoped with catalysts, etc) to flow through the tube out a plurality ofair outlets. An inner electrode of the tube cell extends through alength of the tube cell, and a dielectric layer insulates the innerelectrode from the flow path. An outer electrode directs the flow pathto the plurality of air outlets, which are formed in a shell of theouter electrode. A power generator is coupled to the inner electrode andthe outer electrode and used to generate a dielectric barrier dischargein the flow path to oxidize the air stream. An exhaust stream flowsaround the exterior of the tube cell and intersects with air exiting theplurality of air outlets (outlet air).

In some embodiments, the tube cell has an array of substantiallyidentical tube cells. The exhaust air flow path flows around the arrayof substantially identical tube cells and intersects with outlet airfrom the air outlets on the array of substantially identical tube cells.The array of substantially identical tube cells can include a pluralityof rows of tube cells, or tube cells in a plurality of rows. In someembodiments, each neighboring row of tube cells is offset from oneanother along the exhaust air flow path. Optionally, each neighboringrow of tube cells is offset by at least a square 90° configuration, asquare 45° configuration, a triangle 30° configuration, or a triangle45° configuration. The distance between each tube cell in the array ofsubstantially identical tube cells is preferably optimized to maximizethe immediate mixing of the outlet air and the exhaust air, the distancecan also be optimized to minimize the immediate mixing of the outlet airand the exhaust air. In preferred embodiments, the distance between atleast 3 tube cells of the rows of tube cells conforms to the golden mean(i.e., phi ratio, a+b/a=defφ, or φ=1+√{square root over (5)}/2,abbreviated as 1.618).

The array of substantially identical tube cells is preferably disposedorthogonally to a flow of the exhaust stream, but arrays disposed at anangle (e.g., obtuse, acute, etc) to a flow of the exhaust stream arealso contemplated. Generally, the outer electrode has a cross-sectionalarea or shape of a circle, a tear drop, a diamond, or a curved teardrop. Preferably at least 3 features of the cross-sectional area conformto the golden mean. The cross-sectional area of the outer electrode canalso be twisted along a length of the outer electrode to form a spiral,preferably with at least 3 features of the spiral conforming to thegolden mean along a length of the tube cell.

In some embodiments an outer surface of the outer electrode hasmicro-surface features that accelerate the outlet air flowing around theouter surface of the outer electrode, though micro-surface features thatdecelerate the outlet air flowing around the outer surface of the outerelectrode are also contemplated. In preferred embodiments, thecross-sectional shape and micro-surface features of the outer surface ofthe outer electrode is altered to maximize the immediate mixing of theoutlet air and the exhaust air, but the cross-sectional shape andmicro-surface features can also be altered to minimize the immediatemixing of the outlet air and the exhaust air.

Some embodiments further include an electrode placed downstream (i.e., adownstream electrode) from both the outlet air and the exhaust air, suchthat a voltage is applied to the downstream electrode to entrain gasflow from the tube cell to the downstream electrode. Power to thedownstream electrode can be pulsed to alter a speed of air flowingtowards the downstream electrode.

It should be appreciated that the inventive subject matter uses an arrayof tubes that are placed inside an exhaust stream (e.g., diesel engineexhaust stream, etc), which generate a plasma within them using a(preferably) dry air source that is injected into the tubes from outsidethe exhaust stream (e.g., via air pump, turbo, blower, etc). The exhauststream is shielded from the plasma and therefore few (preferably no)unwanted byproducts (e.g., HNO₂, HNO₃, etc) are created as there islittle (preferably no) source of hydrogen to create OH radicals.Oxidants are further injected into a radical jet stream near the face ofthe catalyst/particulate filter (or similar filters) in an exhaustsystem (e.g., diesel engine exhaust system). It is contemplated thathybrid plasmas can be used to generate oxidants or radicals. Forexample, a blown arc creates NO, which is then oxidized by oxygenradicals generated by a Dielectric Barrier discharge (DBD) placeddownstream of the blown arc. Various tube geometries, surface patterns,and tube arrangements are contemplated to modify drag and mixingcharacteristics in the radical stream, exhaust stream, and mixturestreams. It is further contemplated that high voltage electric fieldsare utilized to entrain stream flow (e.g., mixture stream, etc).

The following description includes information that may be useful inunderstanding the present invention. It is not an admission that any ofthe information provided herein is prior art or relevant to thepresently claimed invention, or that any publication specifically orimplicitly referenced is prior art.

Various objects, features, aspects and advantages of the inventivesubject matter will become more apparent from the following detaileddescription of preferred embodiments, along with the accompanyingdrawing figures in which like numerals represent like components.

The following discussion provides many example embodiments of theinventive subject matter. Although each embodiment represents a singlecombination of inventive elements, the inventive subject matter isconsidered to include all possible combinations of the disclosedelements. Thus if one embodiment comprises elements A, B, and C, and asecond embodiment comprises elements B and D, then the inventive subjectmatter is also considered to include other remaining combinations of A,B, C, or D, even if not explicitly disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a cross section view of an electrode of the inventivesubject matter.

FIG. 2 depicts a cross section view of a single tube cell of theinventive subject matter.

FIG. 3A depicts flow dynamics of an electrode of the inventive subjectmatter.

FIG. 3B additional flow dynamics of an electrode of the inventivesubject matter.

FIG. 3C depicts further flow dynamics of an electrode of the inventivesubject matter.

FIG. 4 depicts cross section views of arrays of tube cells of theinventive subject matter.

FIG. 5 depicts more cross section views of additional arrays of tubecells of the inventive subject matter.

FIG. 6 depicts a dielectric barrier discharge (DBD) tube array of theinventive subject matter.

FIG. 7 depicts a cross section view of a dielectric barrier discharge(DBD) tube array of the inventive subject matter.

FIG. 8 depicts cross section views of single tube cells of the inventivesubject matter.

FIG. 9 depicts a single tube sell of the inventive subject matter.

FIG. 10 depicts another single tube sell of the inventive subjectmatter.

FIG. 11 depicts a cross section of the flow trajectories with respect tothe separation point of the flow instabilities over the outer surface ofthe tube cell.

FIG. 12 depicts additional coherent micro-surface features of theinventive subject matter.

FIG. 13 depicts cross section views of single tube cells of theinventive subject matter.

FIG. 14 depicts yet another array of single tube cells of the inventivesubject matter.

FIG. 15 depicts another array of single tube cells of the inventivesubject matter.

FIG. 16 depicts yet another array of single tube cells of the inventivesubject matter.

FIG. 17 depicts an assembly of a DBD array and a downstream electrode ofthe inventive subject matter.

FIG. 18 depicts yet another array of single tube cells of the inventivesubject matter.

FIG. 19 depicts yet another single tube cell of the inventive subjectmatter.

FIG. 20 depicts waveforms produced by the inventive subject matter.

FIG. 21 depicts an assembly including a DBD array of the inventivesubject matter.

FIG. 22 depicts another assembly including a DBD array of the inventivesubject matter.

FIG. 23 depicts an yet another assembly including DBD arrays of theinventive subject matter.

DETAILED DESCRIPTION

The inventive subject matter provides apparatus, systems, and methods inwhich a tube cell that produces a dielectric barrier discharge tooxidize an air stream can be configured to minimize the mixing ofunwanted byproducts of the generated plasma with an exhaust air stream.The system generates a dielectric barrier discharge within a tube cellto generate oxidants in an environment isolated from the exhaust stream,and directs the generated oxidants to intersect with the exhaust streamto minimize the generation of unwanted byproducts.

The system generally has a power generator coupled to an inner electrodeand an outer electrode with a dielectric layer sandwiched between bothelectrodes. The power generator sends power to the electrodes,generating a dielectric barrier discharge (DBD) plasma within the one ormore tube cells. DBDs contemplated in the inventive subject matter arefilamentary or glow type plasmas having a non-equilibrium state betweenthe temperatures of the electrons and the ions/gas/neutrals. An airstream flows down a length of the dielectric layer within each tubecell, which allows the DBD plasma to oxidize the raw stream, which exitsthe tube cell as an oxidized outlet stream via one or more air outletsof the tube cell. While the air stream is preferably raw (e.g., drawnfrom local environment), it is contemplated that such are stream can betreated (e.g., remove water vapor, heat, cool, ionize, dope withcatalyst, enriched with N, O, H, syngas, noble gases, etc). By shieldingthe oxidation area from the exhaust stream, the generation of unwantedbyproducts is minimized, and plasmas can be generated with lowervoltages and temperatures. Utilizing different geometries, surfacefeatures, and arrayed tube configurations, the system could target, withspecificity, where the outlet air from each tube bell intersects theexhaust stream. Such geometries, surface features, and arrayed tubeconfigurations are illustrated with specificity in the attached claimsand figures.

The system could be tiered, where a raw stream that flows through afirst plasma (e.g. a glide arc plasma) then is entrained or otherwiseguided to flow through the DBD plasma in the arrayed tube cells. Glidearc plasmas are arc plasma discharges that are in a quasinon-equilibrium state between the temperatures of the electrons and theions/gas/neutrals. This provides both equilibrium and non-equilibriumplasmas in the same transient environment. Such plasmas facilitateconditions for catalytic light off at far lower temperature than mostoxidation catalysts, which reduces the requisite temperature foroxidation. For example, an air stream at room temperature could beintroduced into a glide arc plasma generator to generate NO, which isthen introduced into the DBD plasma via one or more tubes of the tubearray, oxidizing NO into NO₂ also at room temperature.

Waves, such as vibrational, electric, radio, light, or ultrasonic wavescould be introduced to some or all of the tubes to enhance mixing andmodify the energy states of the raw stream with the DBD plasma. In someembodiments, the ultrasonic waves could be aimed at a tube inlet, asshown in FIG. 19. In other embodiments, the ultrasonic waves could beaimed generally at a group of arrayed tube cells. Using ultrasonic wavesat a harmonic of the plasma drive frequency could amplify the resonantcoupling effect, increasing the intensity of microvorticies generatedwithin the flow path of a tube cell.

FIG. 1 depicts a cross section of single tube cell 10, which has outerelectrode outlet 1, dielectric electrode layer 2, outer electrode 3, andinner electrode 4. Dielectric electrode layer 2 is made of a dielectricmaterial (e.g., quartz, ceramic, mica, etc). Outer electrode 3 is madeof conductive material, (e.g., Stainless Steel, Nickel, etc). Innerelectrode 4 is also made of conductive material (e.g., Stainless Steel,Nickel, Titanium, Copper, Aluminum, etc). Inner electrode 4 can have adiameter of 0.05 inches, while outer electrode outlet 1 can have adiameter of 0.125 inches. Dielectric electrode layer 2 preferably has adiameter of 0.2 inches. Outer electrode 3 has a wall thickness of 0.05inches and an inner diameter of 0.04 inches. Exhaust flows in thedirection depicted by arrow 6. An oxidant injection area is on the leftportion of tube cell 10, as to not allow for exhaust gas to enter tubecell 10.

FIG. 2 depicts DBD tube 20, having inner electrode 21,standoff/insulator 22, Tube inlet 23, dielectric electrode layer (e.g.,insulator) 24, DBD plasma zone 25, swirl flow dynamic 26 within DBDPlasma Zone 25, tube outlet orifices 27, and oxidants 28 exiting DBDtube 20.

FIGS. 3A-3B depict flow dynamics 30A, 30B, and 30C. 30A has frontalregion 31 which faces the flow, separation point 32, wake region 33. 30Aprovides increased drag and asymmetric mixing dynamics for a flow. 30Bhas reduced drag and symmetric mixing dynamics for a flow. 30C hassymmetrical mixing dynamics for a flow.

FIG. 4 depicts tube cell arrays 40A and 40B comprising tube cells 41Aand 41B, respectively. Tube cross sectional flow area are identified atregions 45A and 45B, and can determine flow characteristics(backpressure, flow velocity, dynamic geometry, vortex sheddingfrequency) on gas flow both inside and outside the tubes.

FIG. 5 depicts tube cell arrays 50A, 50B, 50C, and 50D, having tubes51A, 51B, 51C, and 51D in various orientations. For example, array 50Ahas tubes arranged in a square 90° with respect to flow direction 52A,while array 50B has tubes arranged in a square 45° with respect to flowdirection 52B. Array 51C has tubes arranged in a triangle 30° to flowdirection 52C, while array 51D has tubes arranged in a triangle 45° toflow direction 52D. Tube array configurations can either enhance ordiminish mixing and drag depending on the tubes' correlating positionswith respect to their neighboring tubes.

FIG. 6 depicts DBD tube array 60 having tubes 61, electrical feedthrough62, inlet 63, inlet cross-flow 64, and outlet mixed flow 65. Electricalfeedthrough 62 is an electrode that includes an insulator and mountingmechanism.

FIG. 7 depicts a cross section of DBD tube array 70, having tube array71, electrical feedthrough 72, feedstock inlet 73, and flanges 74.

FIG. 8 depicts single tube cell cross section geometries 80A, 80B, and80C. In 80A, the tube cell has the cross section of a tear drop, while80C has the cross section of a curved tear drop. 80B has the crosssection of a diamond. It should be appreciated that DBD arrays of theinventive subject matter preferably include tubes of the same crosssection shape, but arrays with tubes having different cross sections(e.g., cross sections that complement the shape of adjacent tubes, etc)are also contemplated.

FIG. 9 depicts helical tube surface 90, with tube 91, helical member 92,and oxidant injection point 93.

FIG. 10 depicts helical tube surface 100, with tube 101, and helicalmembers 102 a, 102 b, and 102 c. It is also contemplated that tubesurfaces of the inventive subject matter have tow helical members, orfour or more. It is contemplated that DBD arrays of the inventivesubject matter include one or more tubes having a helical surface asdepicted in FIG. 9 or ten. In some embodiments, most or all tubes in thearray have helical tube surface 90, but it is contemplated that most orall of the tubes alternatively have the shape of helical tube surface100. In some embodiments, a DBD array comprises at least one tube havingthe shape of helical tube surface 90, and at least on tube having theshape of helical tube surface 100.

FIG. 11 depicts coherent micro surface 110, with tube surface 111, aseparation point without coherent surface feature at section 112, and aseparation point with coherent micro-surface features at section 113.Coherent micro-surface features size range from 0.2-10 mm (for length,width, and height), but can be less than 0.2 mm (e.g., 0.15 mm, 0.1 mm,0.05 mm, 0.01 mm) and more than 10 mm (e.g., 11.02 mm, 11.04 mm, 11.06mm, 11.08 mm, more than 12 mm, more than 15 mm, etc). Coherentmicro-surface features are typically spaced from 0.001 mm to 10 mm fromat least one (preferably most, more preferably all) neighboringfeatures, but can also be placed more than 10 mm from neighboringfeatures (e.g., 11.02 mm, 11.04 mm, 11.06 mm, 11.08 mm, more than 12 mm,more than 15 mm, etc). Coherent patterns of micro-surface features onthe surface of the tubes induce a Coanda Effect (e.g., entrained flowthat attaches to a surface within the flow), which entrains and allowsthe gases to attach to the tube surface for a longer period of timebefore it separates. This extends the separation point into the oxidantinjection zone, which can induce better mixing between the oxidants andthe gas stream.

FIG. 12 depicts tube sections 120A and 120B with coherent micro-surfacefeatures. Tube section 120A has coherent micro-surface features 121A and123A along tube surface 122A that accelerate flow. It should be notedthat features 121A and 123A have a rounded structure, and provide a morestreamlined interface for flow in the tube. Tube section 120B hascoherent micro-surface features 121B and 123B along tube surface 122Bthat resist flow. Compared to features 121A and 123A, features 121B and123B are more obstructive to flow in the tube.

FIG. 13 depicts single tube cell geometries 130A and 130B. Thegeometries of 130A and 130B both conform to the golden ratio (i.e., phiratio). For example, the dimension (e.g., width) of 130A at region 133Ais a single unit, while the dimension (e.g., width) at region 134A is1.618 units, such that the ratio of dimensions at region 133A to 134A is1.618 (133A:134A=1.618:1). Similarly, the dimension (e.g., width) of130B at region 133B is a single unit, while the dimension (e.g., width)at region 134B is 1.618 units, such that the ratio of dimensions atregion 133B to 134B is 1.618 (133B:134B=1.618:1). It should beappreciated that further geometries are contemplated by the inventivesubject matter, such that dimensions, shapes, or orientations of thegeometries have elements that conform with the golden ratio.

FIG. 14 depicts single tube array 140. Tube array 140 has tube cells aresized according the golden ratio to complement the natural state of thekarman Vortex Street instability, which sheds consecutive counterrotating vortices that correspond to the golden ratio with respect totheir Strouhal Number. For example, tube 143 has a dimension (e.g.,outer width) at region 144 that is 1 unit, while tube 141 has adimension (e.g., outer width) at region 142 that is 1.618 units, suchthat the ratio of 142 to 141 is 1.618 (142:141=1.618:1).

FIG. 15 depicts single tube array 150 having elements that conform tothe golden ratio. Examining tubes 151, 152, and 153, the center point oftube 151 is spaced one unit (see arrow 154) from the center point oftube 152. Likewise, tube 151 is spaced 1.618 units (see arrow 155) fromthe center point of tube 153. Tube array 150 conforms with the goldenratio as the ratio of spacing between center points of tubes 151 and 153to the spacing between center points of tubes 151 and 152 is 1.618(155:154=1.618:1).

FIG. 16 depicts single tube array 160 having additional elements thatconform to the golden ratio. For example, the spacing between an outerwall of tube 161 to the outer wall of tube 162 is 0.618 units, while thespacing between the outer wall of tube 162 and the outer wall of tube164 is one unit. Thus, the ratio of dimensions between tubes 162 and 164to the dimensions between tubes 161 and 162 is 1.618 (arrow 168:arrow167=1:0.618). Likewise, the the ratio of the spacing between outer wallsof tubes 161 and 163 to the spacing between outer walls of tubes 162 to164 is 1.618 (arrow 166:arrow 168=1.618:1), as is the ratio of thespacing between centers of tubes 162 and 165 to the spacing betweenouter walls of tubes 162 and 164 (arrow 169:arrow 168=1.618:1).

FIG. 17 depicts assembly 170 of DBD array 171 electrically coupled todownstream electrode 172. High voltage AC and/or DC is applied betweenthe tube surface and a downstream electrode can entrain the gas flow tobecome more coherent. This effect is helpful for reducing surface dragand yet increases mixing. It should be appreciated that such voltagescan be pulsed (e.g., at first harmonic, second harmonic, etc) to alterthese effects.

FIG. 18 depicts single tube cell array 180 with single tube cells 181and 182, and arc discharge 182. In some embodiments, there is a plasmaarc in between the tubes and/or between the tubes and another highvoltage electrode for the generation of NO.

FIG. 19 depicts single tube cell 20 further including ultrasonictransducer 191 positioned upstream from tube inlet 192. Micro vortices193 are also formed in the plasma inside single tube cell 20. Ultrasonicwaves increase the plasma energy density by inducing micro-vorticitywithin the gas stream. The surface features guide the micro vorticesinto a coherent structured turbulence. The ultrasonic waves are appliedat a harmonic of the plasma drive frequency for an amplified resonantcoupling effect.

FIG. 20 depicts wave forms 201 generated by plasma driver at resonantfrequency (first harmonic), and wave forms 202 generated by ultrasonictransducer at second harmonic, third harmonic, and fourth harmonicfrequencies. It should be appreciated the current can also be pulsed atelectrodes using these wave profiles.

FIG. 21 depicts assembly 210 having input flow 211 flowing into DBDarray 212, mixing flow 213 flowing into catalyst/particulate filter 214,and output flow 215 flowing out. DBD array 212 has tightly packed tubearrays, for example with flow cross section less than the tube diameterof tubes in the DBD array. Mixing flow 213 has high mixing of radicals(e.g., oxidants) generated from treatment system with exhaust steam.Catalyst/particulate filter 214 has resistive surface features andblunted body type geometry. With the High Mixing Tube Configuration ofassembly 210, the radicals are mixed with the exhaust stream.

FIG. 22 depicts assembly 220 having input flow 221 flowing into DBDarray 222, mixing flow 223 flowing into catalyst/particulate filter 224,and output flow 225 flowing out. DBD array 222 has loosely packed tubearrays, for example with flow cross section more than the tube diameterof tubes in the DBD array. Mixing flow 223 has low mixing of radicalsgenerated from treatment system with exhaust steam. Catalyst/particulatefilter 224 has accelerating surface features and streamlined body typegeometry. With the Low Mixing Tube Configuration of assembly 220, theradicals create a jet stream directed to their targetcatalyst/particulate filter surface with minimal mixing with the exhauststream.

FIG. 23 depicts diesel exhaust plasma array treatment system 230, withair pump 231, electric 3-way valve 232, vortex arc discharge 233, DBDtube arrays 234A and 234B, and clean exhaust stream outlet 235. Air pump231 supplies are to the plasma systems, and can include a blower orturbo. Electric 3-way valve 232 control flow of incoming air to eachplasma array. Vortex arc discharge 233 generates nitrogen monoxide (NO).DBD tube arrays 234A and 234B generate Oxygen radicals. DBD tube array234A is positioned upstream of diesel oxidant catalyst (DOC) andreceives an air stream from air pump 231 and an exhaust stream. DBD tubearray 234B is positioned downstream of 234A and the DOC, and upstream ofa diesel particulate filter (DPF). DBD tube array 234B receives NO richair and a stream that has been treated by DBD tube array 234A and theDOC, which effectively oxidizes NO to nitrogen dioxide (NO₂) and funnelsthe stream in the DPF. Clean exhaust stream outlet 235 outputs gas fromthe DPF that is free of carbon monoxide (CO), NO, hydrocarbons (HC), andsoot. CO, NO, HC, and soot are effectively oxidized by the radicalssupplied by DBD tube arrays 234A and 234B.

As used in the description herein and throughout the claims that follow,the meaning of “a,” “an,” and “the” includes plural reference unless thecontext clearly dictates otherwise. Also, as used in the descriptionherein, the meaning of “in” includes “in” and “on” unless the contextclearly dictates otherwise.

In some embodiments, the numbers expressing quantities of ingredients,properties such as concentration, reaction conditions, and so forth,used to describe and claim certain embodiments of the invention are tobe understood as being modified in some instances by the term “about.”Accordingly, in some embodiments, the numerical parameters set forth inthe written description and attached claims are approximations that canvary depending upon the desired properties sought to be obtained by aparticular embodiment. In some embodiments, the numerical parametersshould be construed in light of the number of reported significantdigits and by applying ordinary rounding techniques. Notwithstandingthat the numerical ranges and parameters setting forth the broad scopeof some embodiments of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspracticable. The numerical values presented in some embodiments of theinvention may contain certain errors necessarily resulting from thestandard deviation found in their respective testing measurements.

As used herein, and unless the context dictates otherwise, the term“coupled to” is intended to include both direct coupling (in which twoelements that are coupled to each other contact each other) and indirectcoupling (in which at least one additional element is located betweenthe two elements). Therefore, the terms “coupled to” and “coupled with”are used synonymously.

Unless the context dictates the contrary, all ranges set forth hereinshould be interpreted as being inclusive of their endpoints, andopen-ended ranges should be interpreted to include commerciallypractical values. Similarly, all lists of values should be considered asinclusive of intermediate values unless the context indicates thecontrary.

The recitation of ranges of values herein is merely intended to serve asa shorthand method of referring individually to each separate valuefalling within the range. Unless otherwise indicated herein, eachindividual value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g. “such as”) provided with respectto certain embodiments herein is intended merely to better illuminatethe invention and does not pose a limitation on the scope of theinvention otherwise claimed. No language in the specification should beconstrued as indicating any non-claimed element essential to thepractice of the invention.

Groupings of alternative elements or embodiments of the inventiondisclosed herein are not to be construed as limitations. Each groupmember can be referred to and claimed individually or in any combinationwith other members of the group or other elements found herein. One ormore members of a group can be included in, or deleted from, a group forreasons of convenience and/or patentability. When any such inclusion ordeletion occurs, the specification is herein deemed to contain the groupas modified thus fulfilling the written description of all Markushgroups used in the appended claims.

It should be apparent to those skilled in the art that many moremodifications besides those already described are possible withoutdeparting from the inventive concepts herein. The inventive subjectmatter, therefore, is not to be restricted except in the scope of theappended claims. Moreover, in interpreting both the specification andthe claims, all terms should be interpreted in the broadest possiblemanner consistent with the context. In particular, the terms “comprises”and “comprising” should be interpreted as referring to elements,components, or steps in a non-exclusive manner, indicating that thereferenced elements, components, or steps may be present, or utilized,or combined with other elements, components, or steps that are notexpressly referenced. Where the specification claims refers to at leastone of something selected from the group consisting of A, B, C . . . andN, the text should be interpreted as requiring only one element from thegroup, not A plus N, or B plus N, etc.

What is claimed is:
 1. A system for treating an exhaust stream,comprising: a tube cell, comprising: an oxidizing flow path for an airstream to flow through the tube out a plurality of air outlets, an innerelectrode extended through a length of the tube cell, a dielectric layerinsulating the inner electrode from the flow path, and an outerelectrode directing the flow path to the plurality of air outlets formedin a shell of the outer electrode; a power generator coupled to theinner electrode and the outer electrode to generate a dielectric barrierdischarge in the flow path to oxidize the air stream; an exhaust streamthat flows around the exterior of the tube cell to intersect with outletair from the plurality of air outlets.
 2. The system of claim 1, whereinthe tube cell composes an array of substantially identical tube cells,and wherein the exhaust air flow path flows around the array ofsubstantially identical tube cells to intersect with outlet air from airoutlets of the array of substantially identical tube cells.
 3. Thesystem of claim 2, wherein the array of substantially identical tubecells comprises a plurality of rows of tube cells.
 4. The system ofclaim 3, wherein each neighboring row of tube cells is offset along theexhaust air flow path from one another.
 5. The system of claim 3,wherein each neighboring row of tube cells is offset in at least one ofa square 90° configuration, a square 45° configuration, a triangle 30°configuration, and a triangle 45° configuration.
 6. The system of claim3, wherein a distance between each of the array of substantiallyidentical tube cells is optimized to maximize the immediate mixing ofthe outlet air and the exhaust air.
 7. The system of claim 3, wherein adistance between each of the array of substantially identical tube cellsis optimized to minimize the immediate mixing of the outlet air and theexhaust air.
 8. The system of claim 3, wherein a distance between atleast 3 tube cells of the rows of tube cells conforms to the goldenmean.
 9. The system of claim 2, wherein the array is disposedorthogonally to a flow of the exhaust stream.
 10. The system of claim 2,wherein the array is disposed at an angle to a flow of the exhauststream.
 11. The system of claim 1, wherein the outer electrode has across-sectional area of at least one of a circle, a tear drop, adiamond, and a curved tear drop.
 12. The system of claim 11, wherein atleast 3 features of the cross-sectional area conforms to the goldenmean.
 13. The system of claim 11, wherein the cross-sectional area ofthe outer electrode is twisted along a length of the outer electrode toform a spiral.
 14. The system of claim 13, wherein at least 3 featuresof the spiral along a length of the tube cell conforms to the goldenmean.
 15. The system of claim 1, wherein an outer surface of the outerelectrode comprises micro-surface features that accelerate the outletair flowing around the outer surface of the outer electrode.
 16. Thesystem of claim 1, wherein an outer surface of the outer electrodecomprises micro-surface features that decelerate the outlet air flowingaround the outer surface of the outer electrode.
 17. The system of claim1, wherein the cross-sectional shape and micro-surface features of theouter surface of the outer electrode is altered to maximize theimmediate mixing of the outlet air and the exhaust air.
 18. The systemof claim 1, wherein the cross-sectional shape and micro-surface featuresof the outer surface of the outer electrode is altered to minimize theimmediate mixing of the outlet air and the exhaust air.
 19. The systemof claim 1, further comprising a downstream electrode placed downstreamfrom both the outlet air and the exhaust air, wherein voltage is appliedto the downstream electrode to entrain gas flow from the tube cell tothe downstream electrode.
 20. The system of claim 19, wherein power tothe downstream electrode is pulsed to alter a speed of air flowingtowards the downstream electrode.